Sen. Richard Blumenthal is blasting longtime NHL Commissioner Gary Bettman over the league's apparent discounting of a link between hockey and brain injuries.

The Connecticut Democrat first reached out to the commissioner in June, asking Bettman nine questions about head injuries in the sport, including the process for diagnosing and treating concussions. Bettman responded with a 24-page letter that outlined the NHL's programs, but also cautioned against "fear mongering."

Blumenthal was not pleased.

"Instead of aggressively seeking to advance the science surrounding concussions, you accuse the 'media,' 'media consultants,' lawyers, and players of 'fear mongering.'" Blumenthal wrote in a follow-up letter to Bettman released Monday. He also referenced chronic traumatic encephalopathy, or CTE, which is a degenerative brain disease that has been found in athletes who have suffered repeated head injuries.

"Your letter suggests that seeking facts about concussions and CTE could instill 'unwarranted fears' that lead to 'depression' and 'suicide,'" Blumenthal wrote. "You suggest that asking questions could frighten parents and others in youth sports."

In his new letter to Bettman, Blumenthal also suggested that the National Hockey League might look to the National Football League for a better approach.

"Your letter stresses how the league willfully refrains from providing ‘warnings’ to players about CTE. Instead, it prioritizes providing 'educational messages' to players to thwart 'misinformation on the topic in the media.' These policies indicate that the NHL would prefer that athletes remain ignorant of potentially very serious threats to their health," Blumenthal wrote. "History proves this path is unsustainable."

Blumenthal called on the commissioner to "re-evaluate and resubmit" his original response to the senator's letter.